Generally teachers are quite experienced with groups of children, and there is often something useful in the teacher's observations. But you might want to learn more about the specifics here. Is it possible to meet with the teacher in a relaxed atmosphere? If the parent and teacher form a "team," it is often more effective in finding solutions. What are the circumstances in which your daughter seems to have problems? What time of day? Is it alone, or with other children? Has the child had a hearing test? Does she appear over-excited, over-tired, angry, distractible? Does she get along well with other children? Does she sleep well? Perhaps you can spend an hour or so one day in the classroom observing your daughter in kindergarten--then you and the teacher might have a better basis of discussion.
I would suggest, too, that you hold off on "disciplining" your daughter until you have a clear idea what is going on with her. Is it possible that the circumstances that led to your being a single mother have had some impact on your daughter and yourself emotionally? Are there stresses in your lives at home right now? Perhaps the teacher can suggest someone at school or elsewhere who can make a more comprehensive evaluation of your daughter's overall situation and give you some recommendations how to proceed. The family doctor is another resource for referrals.
Adding punishment to the mix may backfire, and only give your daughter more reason to "not listen." Giving your child more time, patience, and attention right now may help her settle down into the challenges of school.
The fact that a youngster has not presented problems in previous years does not guarantee that problems may not emerge as the child is older--there are more demands placed on a child's maturity at each new grade.
It is possible, too, that you and your daughter both need some additional supports. Can you reach out for some extra help? Good luck!